The oil and gas exploration and production industry is making increasing use of expandable tubing in a wide variety of applications, including use as casing and liner, in straddles, and as a support for expandable sand screens. Initially, expandable tubing was proposed for use primarily in combination with traditional fixed diameter casing and liner. However, more recently, various proposals have been put forward to utilise expandable tubing to create wells of substantially constant diameter (“monobore” wells), where all or at least a significant proportion of the well is lined with expanded tubing.
Various forms of expansion tools have been utilised to expand tubing downhole, including expansion cones and mandrels which are pushed or pulled through tubing by mechanical or hydraulic forces. Rotary expansion tools have also been used, and these typically feature rollers which are urged outwardly, or which define a fixed diameter, for rolling contact with the tubing to be expanded; the tool is rotated and advanced through the tubing.
It is among the objectives of embodiments of the present invention to provide sections of bore lined with expanded bore-lining tubing of a variety of diameters.